90 



THE SIGNS OF LIFE 



[LECT. 



strongest 



negative 



with a closure time of 0.3 sec. The 

 polarisation occurred after a current of i Daniel passed for 10 

 minutes ; the strongest positive polarisation after a current of 

 20 Groves passed for 0.0/5 sec - '> m tne latter case the E.M.F. 

 appeared to be rather less than that of a muscle-current. 



FlG. 39. T is the time of closure, A the density of the polarising current, 

 + S the strength of the secondary electromotive effect, so that the plane viewed in 

 perspective is the T A Plane. The individual ordinates S are not represented, 

 but only the curves joining the ordinates belonging to given current density and given 

 time (from du Bois-Reymond, Archiv, 1884, p. 15). 



57. Two criticisms. Hermann du Bois' former pupil and 

 untiring critic pounced at once showing and saying in a 

 paper of upwards of sixty closely printed pages of Pfluger's 

 Archiv (vol. xxxiii.), that du Bois' positive polarisation current 

 was in reality a post-anodic action-current. Hering also inter- 

 vened, and said the same thing in two successive papers of the 

 Wiener SitzungsbericJite (i2th and I3th communications, 1883). 



Both du Bois' critics confined themselves to a discussion of 

 the interpretation to be placed upon du Bois' phenomenon, and 

 proved that it was of post-anodic nature, and that the designa- 

 tion of positive polarisation was a very unhappy one. But the 

 critics did not demur to or subtract from the fact itself, nor 



